package com.hackerrank.contests.feb14.challenges.makeitanagram;

import java.util.Scanner;

public class Solution {
	public static void main(String[] args) {
		Scanner in = new Scanner(System.in);
		char[] A = in.nextLine().toCharArray(), B = in.nextLine().toCharArray();
		int[] ca = new int[26], cb = new int[26];
		for(int i = 0; i < A.length; i++)
			ca[A[i] - 'a']++;
		for(int i = 0; i < B.length; i++)
			cb[B[i] - 'a']++;
		int m = 0;
		for(int i = 0; i < ca.length; i++)
			m += Math.abs(ca[i] - cb[i]);
		System.out.println(m);
	}
}
